The unit, which is seeking to be an independent company and is talking with private-equity firms, has annual revenue of $100 million to $200 million, according to one of the sources, who asked not to be named because it’s still early in the sale process.

Sony, which acquired Gracenote in 2008 for about $260 million, may reach an agreement by the end of the year, the source said.

The division is best known for providing the software that lets Apple Inc.’s iTunes quickly identify songs when a user transfers tracks to a computer from a compact disc.

The business has expanded to power many smartphone music applications that compete with Shazam Entertainment Ltd.’s song-recognition service.

Gracenote also is integrating its software into televisions so marketers can learn what a person is watching and target ads based on demographics.

The sources didn’t comment on Sony’s asking price or the potential buyers. Gracenote spokeswoman Sunok Pak said the company doesn’t comment on rumors or speculation. Dan Race, a Sony spokesman, also declined comment. Sally Palmer, a spokeswoman for Qatalyst, didn’t respond to messages seeking comment.

Sony may decide to keep a stake in Gracenote, whose technology is included in many of Sony’s products, including smartphones and televisions, according to another source who was briefed on the matter.

The potential sale, which isn’t finalized and still may fall through, comes as Sony Chief Executive Officer Kazuo Hirai attempts to turn around the struggling company by unifying its sprawling businesses, reducing costs and streamlining operations.

Sony has largely missed the transition to mobile computing dominated by Apple, Samsung Electronics Co. and Google Inc. The Tokyo-based company posted a surprise quarterly loss in October and lowered its forecast for televisions, cameras and computers.

Sony last month said it plans $250 million in cuts at its entertainment division that operates movie and television studios.

Gracenote has operated mostly autonomously since it was acquired, and its software is included in products made by many Sony competitors, including Toshiba Corp. and Microsoft Corp.

The unit keeps a database of audio from songs, television shows and other content, helping gadgets like smartphones, televisions and tablets identify what is playing and, based on the genre, perform tasks such as recommending another song to play or show to watch.

Amazon.com Inc. and Viacom Inc.’s MTV also use Gracenote’s technology.

Gracenote, based in Emeryville, California, is trying to expand its business into the advertising market. It has introduced software that lets TV programmers and marketers recognize what a person is watching, then customize what TV ads are seen based on demographic information and viewing history.

For instance, an automobile company could target ads only toward households that can afford a certain new car.

Quattrone is a veteran Silicon Valley deal maker who recently advised a group of investors that paid $6.9 billion for BMC Software Inc. He also worked with Motorola Mobility Holdings Inc. on its purchase by Google in 2012.